goeduck
Super Member
I have 6", 9" and 15". I use the 6" and 15" bits the most. 15" allows room in the hole so I don't have to cut the top treated rail when doing end braces. They last longer when not cut. Posts are concrete.
I have a hydraulic FEL mounted post hole digger, so similar except you can see better. Much easier than 3 point and best of all, you can reverse the bit. Plus, it will simply stall out hydraulically if the bit hits a root or rock.I gave up using an auger on my tractor. I have a NH skid steer with a 36" auger we plant trees with. I also have a 18" auger if we are doing post frame building or fence posts.